With the exhaustion of the internet protocol version 4 (IPv4) addresses in 2011 and the slow progress in deploying the internet protocol version 6 (IPv6) addresses, the shortage of the public internet protocol (IP) addresses has been a global challenge faced by people in the field of network communication. As a result, oftentimes a large number of users have to share a limited number of available public IP addresses.
Carrier grade network address translation (NAT) has been adopted by many organizations to tackle the shortage of the public IP addresses. Traditionally, there are two approaches to implement carrier grade NAT, or NAT in general: the regular NAT (also known as IP-to-IP NAT) and the network port address translation (NPAT). Under the regular NAT, each private IP address is uniquely translated to a public IP address, and vice versa, such that all of the public IP address ports are reserved for the private IP address. Under the NPAT, each private IP address is no longer uniquely translated to a public IP address. Instead, each private IP address is translated to one or more ports of a public IP address. Because the NPAT mitigates, at least partially, the shortage of the public IP addresses, it has been a popular NAT approach. There are, however, several problems related to this traditional approach.
First, many software applications assume a unique public IP address, and these software applications may not work properly under the NPAT. Therefore, to enhance user experience, it would be ideal in some situations to use the regular NAT instead of the NPAT, especially when and/or where there is relatively large number of available public IP addresses.
Second, under the NPAT, each port associated with a public IP address can be assigned to different private IP addresses (and different ports associated with a private port), so the NPAT generally needs to maintain a network address translation table (NAT table) that records the public IP address, the private IP address, the public IP address port, and/or the private IP address port for each connection. The NAT table can take up lots of the memory space in a system and potentially compromise the throughput of the network.
Therefore, there is a need in the art to provide systems and methods for improving management of the carrier grade NAT server. Accordingly, it is desirable to provide methods and systems that overcome these and other deficiencies of the related art.